This invention relates to improvements in bite block and airway assemblies adapted for use in electro-convulsive therapy of mental patients and also in the administration of gaseous anesthetic to edentulous patients.
During a seizure resulting from electro-convulsive therapy, an extremely strong mandibular contraction occurs requiring protection of the teeth and soft tissues of the mouth and lips. In additon, the possibility of respiratory emergencies during such therapy requires the maintenance of a free approach to the oral cavity and throat throughout the therapy so that resuscitative measures such as the administration of oxygen are possible. For these reasons various types of bite blocks equipped with airways have been used in the past for insertion into the mouth prior to the electroconvulsive therapy. Some of the bite block devices simply contain an air passageway through the mouth piece as shown in the Oberto U.S. Pat. No. 2,521,084. However such products provide inadequate airways partially obstructed by the patient's teeth and permit the patient's tongue to be drawn upwardly against the roof of the mouth shutting off the air passage into the throat. A number of bite block assemblies have attempted to solve this problem by providing a combination airway and tongue depressor tube which extends into the mouth and down the throat of the patient while the bite block is in place. One such assembly is shown in the Godfroy U.S. Pat. No. 2,882,893 wherein an airway-tongue depressor tube is formed integrally with the bite block. The primary problem with such type of assembly is that the depth of insertion of the tube into the throat is fixed when the bite block is in operative position in the mouth, such depth of insertion being insufficient for some patients and too great for other patients. Incorrect depth of insertion in turn can impair the effectiveness of the airway tube and cause serious patient discomfort. Another problem is that the airway tube is of a single fixed structure not necessarily adapted for the particular conduit functions desired, which are variable. For example there are a number of different types of airway-tongue depressor tubes presently on the market having different cross-sectional configurations and channels for performing different functions such as air supply and suction. Therapists may prefer different airway tube configurations for different situations, and an integral bite block and airway tube structure such as Godfroy's does not permit such flexibility.
Bite block assemblies which permit a separate or nonintegral tongue depressor-type airway tube to be inserted into the mouth and extend into the throat while the bite block is in operative position have also previously been used. However such assemblies do not positively hold the position of the airway tube while the bite block is in operative position nor maintain sufficient control of the degree of airway tube insertion throughout the therapy, thereby permitting operational difficulties and patient discomfort similar to those referred to in the previous paragraph.
In the somewhat unrelated field of administering a gaseous anesthetic to an edentulous patient by means of a face mask, it has been discovered that a bite block and airway assembly of the general type discussed above can overcome a certain special problem. The problem referred to is that the patient's absence of teeth tends to permit substantial looseness of the facial tissues in the area of the mouth and cheeks such that the face mask does not form an adequate seal with the face, causing harmful leakage between the anesthetic gas and the surrounding air. The use of a proper bite block and tongue depressor-type airway tube assembly during the administration of the anesthetic can solve the problem by the bite block's filling out the mouth region and correcting the looseness of tissue, thereby overcoming the otherwise defective fit of the face mask. The assembly however must be such as to overcome the foregoing disadvantages of present bite block and airway tube assemblies discussed above.